This invention relates to devices for producing reinforced-concrete pipes, mostly large-diameter ones (4 to 8 m) made use of in constructing sectional pipelines of diverse applications.
Pipe producing plants made according to the present invention can find application as the component of a casting yard on the object being erected immediately at the sites of constructing sectional pipelines of water-accumulating hydroelectric power stations, as well as land reclamation, water-management and some other structures, the amount of which is growing incessantly.
It is common and widespread practice to use the centrifuging method of making reinforced-concrete pipes, wherein concrete mix filled by the feeder into the interior of a rotating mould, is placed uniformly along the inner perimeter of the cylinder-shaped mould due to a centrifugal force thus developed, then gets compacted to assume a preset shape of pipe. However, the centrifuging method of pipe production is actually practicable for pipes not in excess of 1 m in diameter.
Practical experience in producing reinforced-concrete pipes having 4 to 8 m in diameter is now far from being extensive. Thus, one prior-art plant for producing 8 m diameter pipes is known to comprise the following self-contained devices: a stationary form (or mould) with a concrete mix placer device, a station at which reinforcement (rod or wire) is wound onto the moulded pipe, and a station at which a protective coating is applied to the pipe surface.
A disadvantage of the above-mentioned solution (which is an advanced one as a whole) resides in that the production flow-sheet includes such operations as removal of a semi-finished pipe from one of the devices of the production line, its transferring to other devices and accurate setting of said pipe thereon, which adds to the labour consumption of the pipe production process and involves the use of a complicated specialized equipment and highly skilled personnel to attend said equipment.
Furthermore, descending of a heavy-weight workpiece onto a technological production element results in dynamic loads which accelerate wear of the production equipment and impose some additional requirements thereupon. Moreover, the process of filling the mould (having a perimeter of about 25 m) with concrete mix is a very complicated one, while especially sophisticated is the smoothing of the pipe end face to attain a degree of flatness required for a reliable butt-joining of the pipes.